1. Technical Field
The present invention relates to an ink composition, an ink set and an image forming process.
2. Related Art
As a method of recording a color image, inkjet technology is known. Inkjet technology has been applied to the field of office printers, home printers and the like, but it has started to be used in the field of commercial printing in recent years.
As a component included in the ink materials used for inkjet printing, a pigment is widely used. When a pigment is used, water fastness or light fastness of the obtained image and dischargeability of ink from an ejection head are important, and various studies have been made in order to improve these aspects.
For example, as an invention in which dischargeability of ink from an ejection head is improved, Japanese Patent Application Laid-Open (JP-A) No. 2001-348519 discloses an inkjet recording method in which a two-liquid ink is used, the two-liquid ink consisting of an aggregating liquid that includes an aggregating agent, and an ink composition that includes a reactive oligomer as a high-boiling point wetting agent.
Further, as an invention in which water fastness and light fastness of the obtained image are improved, for example, JP-A No. 2004-114692 discloses an actinic energy ray-curable aqueous ink that includes a polymerizable monomer having a specific structure.
However, in the above techniques, positional accuracy of ink dotting with respect to a recording medium has not been taken into consideration and there is room for further improvement in this aspect. In addition, there is a need for further improvement in blocking resistance.
In view of the aforementioned, the present inventors have made intensive studies and, as a result, arrived at the present invention by discovering that when an ink includes a wetting agent at a certain proportion with respect to a polymerizable compound having an acrylamide structure, positional accuracy of ink dotting and blocking resistance of the ink can be improved.